Method and apparatus for applying a material to a wide high-speed web

ABSTRACT

A high-speed apparatus for applying material to cigarette paper during manufacture uses at least two independently operable, moving orifice devices, each positioned to deposit horizontal bands of material on a paper web at the dry end of a Fourdrinier wire. The resulting web may be cut into multiple webs, each web having a width corresponding to the effective width of a moving orifice device. Dynamic optical inspection apparatus evaluates add-on band uniformity, thickness, and/or spacing and adjusts operation of the apparatus accordingly. The apparatus can simultaneously produce both banded and unbanded paper for wrapping tobacco during cigarette manufacturing.

This application claims priority under 35 U.S.C. §119 to U.S.Provisional Application No. 60/664,182 entitled METHOD AND APPARATUS FORAPPLYING MATERIAL TO A WIDE HIGH-SPEED WEB, filed Mar. 23, 2005, theentire content of which is hereby incorporated by reference.

BACKGROUND OF INVENTION

The present invention relates to method and apparatus for applying apredetermined pattern of add-on material to a base web, preferably inthe form of bands, and more particularly, to a high-speed method andapparatus for producing cigarette papers having banded regions ofadditional material.

SUMMARY

A method and apparatus are disclosed for the high-speed production of aweb having banded regions of add-on material, more particularly acigarette paper having stripes of additional cellulosic material addedthereto. The method includes the steps of: preparing a first slurry offibrous material and liquid and delivering that slurry to a moving wireof a paper-making machine, and draining liquid from the first slurry toform a fibrous web advancing at a first nominal linear speed. A secondslurry of add-on material is prepared and delivered to at least one of aplurality of distribution devices, each having a moving belt with one ormore orifices. The belt moves such that its velocity component in thedirection of web movement is substantially the same as the nominallinear speed of the web. The second slurry is deposited as transversestripes on the web through the orifice(s), with the length of eachstripe corresponding to the width of the associated distribution deviceprojected onto the transverse dimension of the web. After drying, theweb may be divided or split into two or more narrower webs forsubsequent use. The transverse stripes of the dry web may be opticallyinspected to evaluate width and spacing characteristics so thatoperation of the distribution devices can be dynamically adjusted toprovide uniform width and spacing of the transverse stripes on the web.

The disclosed apparatus includes at least two applicators for applying apattern of add-on material to the web produced by a paper-makingmachine. Each applicator is positioned at an angle to the direction ofweb movement so that each applicator covers a corresponding portion ofthe web width. Each applicator further includes a continuous beltmovable so as to regulate communication between a reservoir for add-onmaterial and the top of the web. The continuous belt of the applicatoris operable so that the component of its velocity parallel to the websurface in the direction of the web movement corresponds to the linearvelocity of the web movement and each orifice deposits a transversestripe on the web. The apparatus further includes means for selectivelyoperating each of the applicators so that the pattern of stripes can beapplied to the entire width of the web or to a portion of the width.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a paper-making machine constructed inaccordance with a preferred embodiment;

FIG. 2 is a perspective view of a paper constructed in accordance withthe methodologies and apparatus of the preferred embodiment;

FIG. 3 is a perspective view of a cigarette constructed with the paperof FIG. 2;

FIG. 4 is a side view of the moving orifice applicator constructed inaccordance with the preferred embodiment;

FIG. 5 is a breakaway perspective view of the applicator of FIG. 4;

FIG. 6 is a top planar view of tracking control system of the applicatoras viewed in the direction of the double pointed arrow B-B in FIG. 5;

FIG. 7 is a cross-sectional view of the chamber box taken at lineVII-VII in FIG. 4;

FIG. 8 is a detail perspective view of the endless belt of theapplicator shown in FIG. 4; and

FIG. 9 is a detail, partial sectional view of an alternate embodiment ofa chamber box of the applicator of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Existing paper-making machine installations do not have identicalproportions, sizes, running speeds, and the like. To use such machinesfor making banded cigarette paper, the band applying apparatus must fitin within the existing physical arrangement to avoid significantadditional capital investments. Moreover, occasions exist wherecigarette paper machines are needed to produce not only banded paper butalso unbanded paper. When a moving orifice device applies the add-onmaterial to a web, the applicator offset angle becomes small for widermachines, which requires that the applicator operate at speeds that canbe multiples of the nominal wire speed of the paper-making machine. Whenthe paper-making machine operates at speeds of 1500 ft./min and above,the speed requirement for the applicator may cause non-uniformity ofband width and non-uniformity of band spacing. Furthermore, currentpaper inspection techniques for banded paper commonly occur after thepaper-making operation has been completed.

Referring to FIG. 1, a preferred embodiment comprises a cigarette papermaking machine 2 which is operable to manufacture banded paper 3 (seeFIG. 2) having uniform width bands 5 spaced from one another. Suchbanded paper 3 can be used in the manufacture of cigarettes (see FIG. 3)where the bands 5 comprise regions designed to self-extinguish thecigarette. The paper making machine 2 (FIG. 1) preferably includes ahead box 4 operatively located at one end of a Fourdrinier wire 6, afeed stock slurry is prepared and delivered to a source of feed stockslurry such as a run tank 8 in communication with the head box 4. Themachine 2 also includes at least two distribution devices, such asmoving orifice applicators 10, 10′, in operative communication withsource of prepared add-on slurry such as a day tank 12.

The head box 4 can be one typically utilized in the paper makingindustry for laying down cellulosic pulp upon the Fourdrinier wire 6. Inthe usual context, the head box 4 communicates with the run tank 8through a plurality of conduits 14. Preferably, the feed stock from therun tank 8 constitutes a refined cellulosic pulp such as a refined flaxor wood pulp as is the common practice in the cigarette paper-makingindustry. That pulp normally constitutes a mixture of water, fibers, andadditives including fillers such as chalk.

The Fourdrinier wire 6 moves in a longitudinal direction, has a widthtransverse to that longitudinal direction, and operates at a generallyconstant nominal linear speed. The first slurry from the run tank 8 isdelivered through the head box 4 to the moving Fourdrinier wire 6.

The Fourdrinier wire 6 carries the laid slurry pulp from the head box 4along a path in the general direction of arrow 16 in FIG. 1. As the wire6 advances, liquid water drains from the pulp through the wire 6 underthe influence of gravity to form a fibrous web. Vacuum boxes 18 may beprovided at some locations along the Fourdrinier wire 6 to assist inremoval of water from the slurry, as is the established practice in theart of cigarette paper-making. At some point along the Fourdrinier wire6, sufficient water has drained and/or been removed from the base webpulp to establish what is commonly referred to as a dry line 20. At thedry line 20, the texture of the slurry transforms from one of a glossy,watery appearance to a surface appearance more closely approximatingthat of the finished base web (but in a wetted condition). At about thedry line 20, the moisture content of the pulp material is approximately85 to 90%, which may vary depending upon operating conditions and thelike. The surface of the web 22 is generally planar and is supported bythe Fourdrinier wire 6.

Downstream of the dry line 20, the base web 22 separates from theFourdrinier wire 6 at a couch roll 24. From there, the Fourdrinier wire6 continues on the return loop of its endless path. Beyond the couchroll 24, the base web 22 continues on through the remainder of the papermaking system including the drying section 27 which further dries andpresses the base web 22 and surface conditions it to a desired finalmoisture content and texture. Such drying apparatus are well known inthe art of paper making and may include drying felts 26 and the like.

At the very end of the paper-making machine, suitable conventionalreeling apparatus 28, 29 is provided to collect the paper onto spoolsfor subsequent processing and/or use. Such reeling apparatus 28, 29 iswell known in the art of paper making.

During the paper-making process, it is sometimes desirable to apply apattern to the web before the web is dried so that the pattern becomespart of the paper web itself rather than a surface treatment such as,for example, printing. A preferred pattern comprises a plurality ofuniformly spaced, transverse bands on the base web. The bands may, forexample, comprise an add-on material useful in affecting combustibilityof the resulting paper web. Materials used to accomplish self-extinctionof cigarettes are candidates for such patterns.

Paper-making apparatus currently used for making cigarette paper differin many ways. Paper-making machines vary in terms of the transversewidth of the Fourdrinier wire 6, the nominal speed of the Fourdrinierwire 6, longitudinal spacing between the headbox 4 and the couch roll24, and longitudinal spacing between the dry line 20 and the couch roll24, to name just a few. For example, paper-making apparatus may havewire widths ranging from less than 3 meters to greater than 5 meters.Similarly, machines may have Fourdrinier wire operating at linear speedless than 400 ft./sec. to greater than 1500 ft./sec. For purposes ofthis description, widths greater than 3 meters are considered wide andlinear speeds exceeding 500 ft./min are considered high speed.

Processes and apparatus for applying patterns of add-on material to aweb at the wet end of a paper-making machine are preferably to adaptableto accommodate idiosyncrasies of existing machine installations. Toapply add-on material to wide and high speed paper-making machines, aplurality of distribution devices are used that apply a pattern of bandsin zones across a base web. Each of the distribution devices canincorporate features of a moving orifice applicator for add-on materialis described in commonly assigned U.S. Pat. No. 5,997,691, issued Dec.7, 1999 to Gautam et al., which is hereby incorporated herein by thisreference thereto.

With reference to FIG. 1, two or more applicators, such as the movingorifice applicators 10, 10′, are provided between the dry line 20 andthe couch roll 24 to apply separate patterns of add-on material to theweb 22. Each applicator is operable to apply the pattern to acorresponding portion of the width of the web. The applicators 10, 10′may be parallel to one another and offset as shown. The applicators 10,10′ may also be offset from one another longitudinally along theFourdrinier wire 6 as necessary to accommodate existing obstructions inthe site for the paper-making machine. The applicators 10, 10′ may bepositioned at the same or different angles with respect to thelongitudinal direction of the machine, if desired.

Since the required length of such a moving orifice applicator 10, 10′ isa function of (i) the width of the web, (ii) the longitudinal speed ofthe paper-making machine, and (iii) the angle between the applicator andthe longitudinal direction at which the web advances along theFourdrinier wire, the use of multiple applicators reduces the physicallength needed along the Fourdrinier wire by the reciprocal of the numberof applicators used. Thus, multiple applicators can be used to obviatelimitations that might otherwise be imposed by the above-noted physicalcharacteristics of paper-making machines.

An applicator offset angle can be defined as the acute angle between thelongitudinal direction of movement of the Fourdrinier wire and angleddirection of movement of the belt of the moving orifice device.Alternatively the applicator offset angle can be defined as thecomplement to the acute angle between the longitudinal direction of themachine and the plane within which the edge of the moving orifice beltoperates. For low values of the applicator offset angle, the linearspeed of the moving orifice belt becomes a multiple of the nominallinear speed of the Fourdrinier wire. For example, at an applicatoroffset angle of 30°, the belt speed is twice the nominal linear wirespeed; for an applicator offset angle of about 19.5°, the belt speed isthree times the nominal linear wire speed; and for an applicator angleof about 14.5°, the belt speed if four times the nominal linear wirespeed. High-speed paper-making machine installations operate at nominallinear speeds of 1400 to 1500 ft/sec. At the required band speeds forlow applicator offset angles, fluid mechanics characteristics of theadd-on material and physical limitations of the applicator operation cancombine to cause splatter and/or insufficient uniformity in thedeposited pattern. Multiple applicators 10, 10′ can be employed allowingthe applicator offset angle for each applicator to be increased therebyreducing the belt speed to acceptable levels so that splatter is avoidedand the deposited pattern is uniform.

Moreover, where the applicators 10, 10′ are selectively operable, i.e.,they can be used simultaneously, separately, or turned off, and thepaper-making operation can produce a banded pattern across the web, abanded pattern on only a portion of the web, or unbanded paper acrossthe web. For example, where both banded paper and non-banded paper areneeded simultaneously for cigarette manufacture, the paper-makingmachine 2 can be operated with one of the two applicators 10, 10′operating and the other applicator being idle. In this way, half theresulting cigarette wrapper product can be banded and the other halfunbanded.

Details of the moving orifice applicator 10 will now be described. Itwill be understood by those of ordinary skill in the art that thedetails of each additional moving orifice applicator 10′ aresubstantially the same, with the possible exception of length. Referringnow to both FIGS. 1 and 4, add-on slurry from the day tank 12 isdelivered to the moving orifice applicator 10. Preferably, the movingorifice applicator 10 comprises an elongate chamber box 30 forestablishing a reservoir of add-on slurry in an oblique relation acrossthe path 16 of the Fourdrinier wire 6. That reservoir receives theadd-on slurry from the day tank 12. The moving orifice applicator 10also includes an endless continuous perforated steel belt 32, whosepathway is directed about a drive wheel 34 at the downstream end of theapplicator, a guide wheel 36 at the apex of the moving orificeapplicator 10, and a follower wheel 38 at the upstream end of thechamber box 30, i.e., opposite from the drive wheel 34. Upstream anddownstream are viewed as being relative to movement of the Fourdrinierwire 6 and the web 22.

The endless belt 32 moves through a bottom portion of the chamber box 30and, as it leaves the chamber box 30, the belt 32 moves through acleaning box 42. Then, the belt 32 moves toward the drive wheel 34 andcontinues along the remainder of its circumlocution.

The belt 32 (see FIG. 8) preferably has a plurality of orifices spaceduniformly along the length thereof. As each perforation or orifice 44(FIG. 8) of the belt 32 passes through the bottom portion of the chamberbox 30, the orifice 44 communicates with the reservoir of add-on slurryestablished in the chamber box 30. At such time, a stream 40 (FIG. 4) ofadd-on slurry discharges from the orifice 44 as the orifice 44 traversesthe length of the chamber box 30. The discharge stream 40 impinges uponthe base web 22 passing beneath the moving orifice applicator 10 so asto deliver or create a transverse band of additional (add-on) materialupon the base web 22. The operational speed of the belt 32 varies fromone layout to another, but by way of example, the belt 32 is driven atapproximately 1111 feet per minute when the Fourdrinier wire moves atapproximately 500 feet per minute and the chamber box 30 is orientedwith an offset angle of 27° relative to the direction of the wire. Thespacing of the orifices 44 along the belt 32 and the operational speedof the belt 32 are selected such that a plurality of streams 40, 40′emanate simultaneously from beneath the chamber box 30 during operationof the moving orifice application. Because of the oblique orientation ofthe moving orifice applicator relative to the path 16 of the base web 22and the relative speeds of the Fourdrinier wire 6 and the endless belt32, each stream 40 of add-on material will create a band of add-onmaterial upon the base web 22, where the band has a length correspondingto the operational length of the moving orifice applicator 10. Thatoperational length is the length in the direction transverse of the wire6 through which the orifice 44 can deposit add-on material. At the abovespeeds and angle, the moving orifice applicator 10 will repetitivelygenerate or deposit transverse bands of add-on material that areoriented normal to a longitudinal edge of the base web 22 and uniformlyspaced from one another along the web 22. In combination, the multipleapplicators 10, 10′ are operable to deposit aligned or offset bandssubstantially across the entire width of the Fourdrinier wire 6. Ifdesired, the angle and/or relative speeds may be altered to producebands which are angled obliquely to the edge of the base web 22.

After the belt 32 exits from the chamber box 30, the portions of thebelt 32 adjacent each orifice 44 are cleansed of entrained add-on slurryat the cleaning station 42. The belt 32 and each associated orifice thenproceed along the circuit of the endless belt 32 to reenter the chamberbox 30 to repeat an application of a band upon the base web 22.

Referring particularly to FIG. 1, the moving orifice applicator 10 ispreferably situated obliquely across the Fourdrinier wire 6 at alocation downstream of the dry line 20 where condition of the base web22 is such that it can accept the add-on material without the add-onmaterial dispersing itself too thinly throughout the local mass of thebase web slurry. The applicator 10 is uniformly spaced above the web 22such that the stream 40, 40′ of add-on material emanating from theorifices 44 falls through the same distance between the applicator 10and the planar upper surface of the web 22. At that location of theapplicator 10, the base web 22 retains sufficient moisture content(approximately 85 to 90%) that the add-on slurry is allowed to penetrate(or establish hydrogen bonding) to a degree sufficient to bond andintegrate the add-material to the base web 22.

Preferably, a vacuum box 19 located beneath the chamber box 30 of themoving orifice applicator 10 extends coextensively with the applicatorproviding local support for the Fourdrinier wire 6 as well asfacilitating the bonding/integration of the add-on slurry with the baseweb 22. The vacuum box 19 is constructed in accordance with designscommonly utilized in the paper making industry (such as those of thevacuum boxes 18) The vacuum box 19 operates at a relatively modestvacuum level, preferably at approximately 60 inches of water or less.Optionally, additional vacuum boxes 18′ may be located downstream of themoving orifice applicator 10 to remove the additional quantum of waterthat the add-on slurry may contribute. It has been found that much ofthe water removal from the add-on material occurs at the couch roll 24where a vacuum is applied of approximately 22-25 inches mercury.

The moving orifice applicator 10 is supported in its position over theFourdrinier wire 6 in a suitable conventional way so that the movingorifice applicator 10 may be lowered consistently to a desired locationabove the Fourdrinier wire 6, preferably such that the bottom of thechamber box 30 clears the base web 22 on the Fourdrinier wire 6 byapproximately one to two inches, preferably less than 1.5 inch.

Preferably, the chamber box 30 has a length selected such that thechamber box 30 covers a portion of the width of the web 22, measuredtransverse to the paper-making machine. The multiple applicators 10, 10′are arranged such that the adjacent ends of their respective chamberboxes 30 lie above a common longitudinal line in the web 22 so thattransverse bands of adjacent applicators 10, 10′ do not overlap. Theapplicators 10, 10′ are also arranged such that the outermost end of theapplicator adjacent to the corresponding web edge extends beyond theedge of the base web 22. When there are three or more applicators, theedges of the outermost applicators have an overlapping relationship withthe web edges. Ends of interior applicators can overlap or not overlapin the transverse direction across the base web. The over-extension ofthe chamber boxes 30 at the web edges assures that any fluiddiscontinuities existing or arising at the end portions of the chamberbox 30 do not affect the discharge streams 40 as the streams 40 depositadd-on material across the base web 22. By such arrangement, any errantspray emanating from the ends of the chamber box 30 occurs over edgeportions of the base web 22 that are trimmed away at or about the couchroll 24. Likewise, overlapping or non-overlapping of the bands acrossthe base web can be trimmed to provide continuous reels of uniformlybanded paper.

The vertical support framework for the moving orifice applicators 10,10′ may be pivotal about the other so as to adjust applicator offsetangle for the applicators 10, 10′ relative to the Fourdrinier wire 6.However, the preferred practice involves fixing the vertical supportframework and only adjusting the speed of endless belt 32 in response tochanges in operating conditions of the paper making machine 2.

The chamber box 30 receives add-on slurry from the day tank 12 at spacedlocations along the chamber box 30. The reservoir of the chamber box 30may also include a plurality of linearly arranged compartments throughwhich the endless belt 32 passes. Uniform pressure is preferablymaintained along the length of the chamber box 30 by the interaction ofa flow distribution system 60, a pressure monitoring system 62 and aprogrammable logic controller 64 such that the pumping action of thebelt 22 and other flow disturbances along the length of the chamber box30 are compensated locally and continuously to achieve the desiredpressure uniformity throughout the length of the chamber box 30. A maincirculation pulp 15 delivers add-on slurry from the day tank 12 to theflow distribution system 60.

Details regarding how the controller initiates and maintains uniformpressure along the chamber box 30 are known, see, e.g., commonlyassigned U.S. Pat. No. 5,997,691.

A selectable speed motor drives the drive wheel 34 and is operativelyconnected therewith by a suitable conventional drive belt. Preferably,the motor is supported by the framework of the moving orifice applicator10, and both the motor and the drive belt are encased within a housingso as to capture any extraneous material (such as bits of slurry) thatmay find its way to and be otherwise flung from the drive system for thedrive wheel 34.

The drive wheel 34 is advantageously positioned at the downstream end ofthe chamber box 30 along the pathway of the belt 32 so that the belt 32is pulled through the chamber box 30. A significant degree of thedirectional stability is achieved by the close fit between the belt 32and the elongate chamber box 30 throughout the length of the box 30.However, precise control of the tracking for the belt 32 about itspathway circuit is effected by placement of an infrared proximity sensor54 at a location adjacent the guide wheel 36. The infrared proximitysensor 54 comprises an emitter 56 and a sensor 58 which are mutuallyaligned relative to one of the edges of the belt 32 such that if thebelt strays laterally from its intended course, a signal from the sensoris affected by a relative increase or decrease in the interference ofthe edge with the emitter beam. A controller 59 communicates with thesensor 58, interprets changes in the signal from the sensor 58 andadjusts the yaw of the guide wheel 36 about a vertical axis so as toreturn the edge of the belt 32 to its proper, predetermined positionrelative to the beam of the emitter 56.

Referring now also to FIG. 6, the guide wheel 36 rotates about ahorizontally disposed axle 36 a, which itself is pivotal about avertical axis at a pivotal connection 57 by the controlled actuation ofa pneumatic actuator 61 The actuator 61 is operatively connected to afree end portion 36 b of the axle 36 a and is responsive to signalsreceived from the controller 59. Preferably, both the pivotal connection57 and the actuator 61 are fixed relative to the general framework ofthe applicator 10 during operation the applicator 10; and a connection54 a is provided between the sensor 54 and the free end 36 b of the axle36 a so that the sensor 54 rotates as the yaw of the guide wheel 36 isadjusted. The connection 54 a assures that the sensor 54 remainsproximate to the edge of the belt 32 as the guide wheel 36 undergoesadjustment.

Preferably, the actuator 61 and the pivotal connection 57 are affixed ona plate 39 a which is vertically displaceable along fixed verticalguides 39 b and 39 c. Preferably, releasable, vertical bias is appliedto the plate 39 a so as to urge the guide wheel 36 into its operativeposition and to impart tension in the endless belt 32.

Along the return path of the endless belt 32, from the drive wheel 34over the guide wheel 36 and back to the follower wheel 38, the belt 32is enclosed by a plurality of housings, including outer housings 68, 68′and a central housing 70 which also encloses the infrared proximitysensor 54 and the controller 59 of the tracking system 55. The housing68, 68′ and the housing 70 prevent the flash of errant slurry upon thebase web 22 as the belt 32 traverses the return portion of its circuit.

Referring particularly to FIG. 4, the housings 70 and various othercomponents of the applicator 10 (such as the wheels 34, 36 and 38; thechamber box 30; the cleaning box 42; and the motor 52) are supported byand/or from a planar frame member 72. The planar frame member 72 itselfis attached at hold-points 73, 73′ to a cross-member (an I-beam, boxbeam or the like), which cross-member is supported by the verticalsupport framework. In the alternative, an I-beam member or a box beammember may be used as a substitute for the frame member 72, with thechamber box 30 and other devices being supported from the beam member.

Referring to FIG. 5, in either support arrangement, the chamber box 30is preferably hung from the support member with two or more, spacedapart adjustable mounts 77 a, 77 b that permit vertical and lateraladjustment (along arrows y and x in FIG. 5, respectively) of each end ofthe chamber box 30 so that the chamber box 30 may be accurately leveledand accurately angled relative to the Fourdrinier wire, and so that thechamber box 30 may be accurately aligned with the belt 32 to minimizerubbing.

Referring now to FIG. 7, the chamber box 30 includes at its bottomportion 76 a slotted base plate 78 as well as first and second wearstrips 79 and 80, which cooperate with the base plate 78 to define apair of opposing, elongated slots 81 and 82 that slidingly receive edgeportions of the endless belt 32. Preferably, the elongate slots 81 and82 are formed along a central bottom portion of the base plate 78, butalternatively, could be formed at least partially or wholly in the wearstrips 79 and 80.

The central slot 84 in the base plate 78 terminates within the confinesof the chamber box 30 adjacent to the end portions 50, 50′ of thechamber box 30. Preferably, each terminus of the central slot 84 isscalloped so as to avoid the accumulation of slurry solids at thoselocations. The width of the central slot 84 is selected so as tominimize exposure of the fluid within the chamber box 30 to the pumpingaction of the belt 32. In the preferred embodiment, the slot isapproximately ⅜ inch wide, whereas the diameter of the orifices 44 inthe endless belt 32 is preferably approximately 3/32 inch.

Each wear strip 79, 80 extends along a corresponding opposite side ofthe bottom portion 76 of the slurry box 30, co-extensively with the baseplate 78. An elongate shim 86 and a plurality of spaced apart fasteners88 (preferably bolts) affix the wear strips 79, 80 to the adjacent,superposed portion of the base plate 78. However, the orifices 44 canhave any desired configuration such as symmetrical or asymmetricalnon-circular openings.

The tolerances between the respective edge portions of the belt 32 andthe slots 81, 82 are to be minimized so as to promote sealing of thebottom portion 76 of the chamber box 30. However, the fit between thebelt 32 and the slots 81, 82 should not be so tight as to foment bindingof the endless belt 32 in the slots 81, 82. In the preferred embodiment,these countervailing considerations are met when the slots 81, 82 areconfigured to present a 1/16 inch total tolerance in a width-wisedirection across the endless belt 32. In the direction normal to theplane of the belt, the belt has preferably a thickness 0.020 inch,whereas the slots 81, 82 are 0.023 inch deep. These relationshipsachieve the desired balance of proper sealing and the need for facilepassage of the belt 32 through the bottom portion 76 of the chamber box30.

Preferably, the wear strips 79, 80 are constructed from ultra highmolecular weight polyethylene or Dalron.

Included within the confines of the chamber box 30 are beveled inserts89, 90 which extend along and fill the corners defined between the baseplate 78 and each of the vertical walls 91, 92 of the chamber box 30.The inserts preferably present a 45 degree incline from the verticalwalls 91, 92 toward the central slot 84 of the base plate 78. Thisarrangement avoids stagnation of fluid in the confines of the chamberbox 30, which would otherwise tend to accumulate the solid content ofthe slurry and possibly clog the chamber box 30 and the orifices 44 ofthe endless belt 32.

Near the bottom portion 76 of the chamber box 30, a plurality ofspaced-apart pressure ports 94 communicate the pressure monitoringsystem 62 with the interior of the slurry box 30.

Along the upper portion of the chamber box 30, a plurality ofspaced-apart feed ports 96 are located along the vertical wall 91. Thefeed ports 96 communicate the flow distribution system 60 with theinterior of the slurry box 30. Preferably, the feed ports 96 are locatedclose to the lid plate 31 of the chamber box 30. The flow distributionsystem 60 has been noted in reference to FIG. 1.

The feed ports 96 are spaced vertically by a distance h above thelocation where the endless belt 32 traverses through the bottom portion76 of the chamber box 30. The feed ports 96 introduce slurry into thechamber box 30 in a substantially horizontal direction. The verticalplacement and the horizontal orientation of the ports 96 dampensvertical velocity components in the fluid at or about the region ofendless belt 32 at the bottom portion 76 of the chamber box 30. Thearrangement also decouples the discharge flows 40 through the orifices44 from the inlet flows at the feed ports 96.

The height h in the preferred embodiment is approximately 8 inches ormore; however, the vertical distance h between the feed ports 96 and theendless belt 32 may be as little as 6 inches. With greater distances forh, there is less disturbance and interaction between the fluid adjacentthe endless belt 32 and the fluid conditions at the feed ports 96.

In the preferred embodiment, twelve feed ports 96 are used, but theapplicator is workable with as few as six inlet feed ports 96. Althoughnot preferred, the applicator is expected to function with as few asfour inlet feed ports 96. The number of feed ports 96 depends upon theportion of the web width the particular applicator must cover. Thepreferred spacing between the feed ports 96 is approximately twelveinches and preferably not greater than approximately twenty-four inches,although it is possible to operate with even greater separation.

Referring now to FIG. 8, each orifice 44 along the endless belt 32includes a beveled portion 45 adjacent the side of the endless belt 44facing into the chamber box 30. With such an arrangement, the solidscontent of the slurry is not allowed to collect at or about the orifices44 during operation of the applicator 10. More particularly, slurryfiber is not allowed to collect about the orifice and deflect the jetsof slurry being discharged. Accordingly, the beveled portions 45 of theorifices 44 promote consistent delivery of slurry from the applicator 10and reduce malfunctions and maintenance.

Referring now to FIG. 9, in an alternate embodiment of the chamber box30′, the vertical walls 91′, 92′, together with the base plate 78′ andinclined beveled elements 89′, 90′ cooperate with a retractable armature100, which supports an elongate wear strip 102 at its operative endportion. The elongate wear strip 102 extends the length of the chamberbox 30′ and is supported at spaced locations along each side of thechamber 30′ by a plurality of retractable armatures 100 and 101. In thisembodiment, the wear strips 79′ and 80′ are mounted upon and areretractable with the armatures 100 and 101, respectively. In FIG. 9, thearmatures 100 along one side of the chamber box 30 are shown in aretracted position, while the armatures 101 along the opposite side ofthe chamber box 30′ are shown in an engaged position, where therespective wear strip 90′ is biased against the base plate 78′. Inactual operation, the armatures 100 and 101 are pivoted between theretracted and engaged positions simultaneously.

Each retractable armature 100, 101 is pivotally mounted upon one or apair of vertical flanges 106, which preferably provides support for anactuator mechanism 107 for moving the retractable armature 100, 101 froman operative, engaging position where the wear strips 89′, 90′ are urgedagainst base plate 78′ to a retracted position where the wear strips89′, 90′ are spaced away from the base plate 78′ and the endless belt32′.

The actuator mechanism 107 is preferably an air cylinder 108 which isoperatively connected to the pivot arms 109, 110 of the armatures 100and 101, respectively. Other mechanical expediencies could be selectedfor pivoting the retractable armatures 100 and 101, as would be readilyapparent to one of ordinary skill in the art upon reading thisdisclosure.

An elastomeric seal 104 is provided between the lower portions of thechamber box walls 91′, 92′ and the base plate 78′ so as to create afluid-proof seal about the entire periphery of the base plate 78′.

In operation, all of the armatures 100, 101 along both sides of thechamber box 30′ are pivoted simultaneously so that the wear strips 79′,80′ are moved as units to and from their operative and engagedpositions. The retractable armatures 100, 101 facilitate quick andspeedy maintenance, repair and/or replacement of the endless belt 32′,the wear strips 79′, 80′ and the base plate 78′.

As discussed above, after the web 22 leaves the couch roll 24 (see FIG.1), the web advances through the dryer section 27 where additionalmoisture is removed and the cellulosic fiber web is dried to the desiredmoisture content level. As the web 22 leaves the dryer section 27, itpasses through and optical inspection means 120 that examines thetransverse bands of add-on material and evaluates the uniformity of bandwidth and uniformity of spacing between adjacent bands or lines. Toeffect this optical inspection, the optical inspection system mayinclude a plurality of suitable conventional cameras deployed in alinear array above the web 22 and directed downwardly at the top surfaceof the web within a housing 122. The cameras can be uniformly spacedfrom one another so that the camera position is indicative of thelateral location on the web, i.e., a longitudinal zone of the web. Inaddition, the field of view for adjacent cameras may slightly overlap toinsure that the entire width of the web is subject to the opticalinspection. By way of example, 16 cameras may be deployed in the array.

The optical inspection system 120 communicates its inspection signalsthrough suitable conventional cabling 124 to the programmablecontrollers 64, 64′ of the applicators. The longitudinal zones of theweb monitored by the cameras of the optical inspection system 120correspond to regions of the applicators 10, 10′ fed by the feed ports96. Thus, if lack of line-width uniformity is detected in a portion of aline, the programmable controllers use the feedback signal from theinspection system 120 to appropriately adjust the add-on materialsupplied to the feed port 96 corresponding to the longitudinal zone ofthe web where the lack of band-width uniformity was detected. Thisadjustment at the feed port 96 occurs dynamically, i.e., while the paperis being produced thereby avoiding production of large quantities ofdefective paper that must be discarded or reprocessed. In addition, thedynamic feedback adjustment and control can avoid the need forpost-manufacture inspection of the paper.

If lack of band-spacing uniformity is detected by the optical inspectionsystem 120, then the feedback signals are employed to appropriatelyadjust the linear speed of the moving orifice belt 32 of the appropriateapplicator 10, 10′. In that manner, the band-spacing of the transversebands on the web can be dynamically adjusted so to remain within thedesign tolerances for the band-to-band spacing. Again, the dynamicfeedback adjustment and control for band spacing provided by the opticalinspection system may be used to avoid post-manufacture inspection ofthe manufactured paper.

After passing through the optical inspection system 120, the web entersa splitter 125 for dividing the web 22 into two or more longitudinal webportions 130, 132. The splitter 125 may, for example, include anappropriate number of slitting disks 126 positioned laterally over theweb 22 to cut the web into the desired longitudinal portions 130, 132.The splitters disk 126 may engage an anvil roll 128 so that the disk 126and the roll 128 cooperate to sever the web at the position of the disk126 as the web passes between the disk 126 and the anvil 128.

While a single splitting disk 126 is depicted, that arrangement would beappropriate for an installation using two moving orifice applicators 10,10′. Where, for example, three applicators are used, it may be desiredto split the web 22 into three longitudinal portions. In that instance,two splitter disks 126 would be used with the same anvil roll 128, thedisks being spaced from one another to provide web portions with thedesired width.

Downstream of the splitter 125, the individual web portions 130, 132 arecollected by corresponding reeling apparatus 28, 29. Here again, whileonly two reeling apparatuses are shown, one would be provided for eachlongitudinal web portion in applications where the original web 22 isdivided into more than two portions.

In manufacturing scenarios where both banded and unbanded papers areneeded, the paper manufacturing machine can be operated with one of theapplicators 10, 10′ being inactive. As a result, one longitudinalportion 132 of the web may be banded and collected while the otherlongitudinal portion 130 of the web is unbanded and collectedsimultaneously. This capability increases the manufacturing flexibilityof the paper making apparatus.

The general method of making patterned paper according to the disclosurehas been described in conjunction with the foregoing description of theapparatus. Further, the operation of the cigarette paper-making machineand method of the preferred embodiment typically uses flax feedstock.Nevertheless, the apparatus and associated methodologies are readilyworkable with other feedstocks such as hardwood and softwood pulps,eucalyptus pulps and other types of pulps used in the paper makingindustry. The alternate pulps may have different characteristics fromflax, such as differences in average fiber length, which may necessitateadjustment of the degree of refining in the preparation of the basesheet slurry with some pulps. Regardless what type of pulp is used,add-on slurry must be processed sufficiently to avoid fiber build-up ator about the orifices 44 of the belt, which in turn avoids jetdeflections at the orifices 44.

Because the flow of the fluid stream 40 emanating from each orifice 44as the orifice 44 passes along the bottom portion of the chamber box 30is proportional to the pressure differential across the orifice 44, itis desirable that fluid pressure be established and then held asuniformly as possible along the entire journey of each orifice 44 alongthe bottom portion 76 of the chamber box 30.

A new high speed method and apparatus for applying a material to a webhas been described in this specification. It will be apparent to thoseskilled in the art that numerous modifications, variations,substitutions, and equivalents exist for various features of theinventions recited in the appended claims. Accordingly, all suchmodifications, variations, substitutions and equivalents that fallwithin the spirit and scope of the invention as set forth in theappended claims are intended to be embraced by the appended claims.

1. A method of manufacturing a web having an applied pattern of add-onmaterial, the method comprising the steps of: preparing a first slurryof fibrous material and liquid; delivering the first slurry to a movingwire having a longitudinal direction, a wire width transverse to thatlongitudinal direction, and a nominal linear speed; draining the liquidfrom the first slurry through the moving wire to form a fibrous web;preparing a second slurry of add-on material; operating at least one ofa plurality of distribution devices, each device having a continuousbelt with a plurality of spaced-apart orifices therethrough, areservoir, a principal length, and angled with respect to thelongitudinal direction such that each distribution device covers acorresponding portion of the wire width; delivering the add-on slurry tothe reservoir of at least one distribution device; moving the continuousbelt with a nominal band speed having a velocity component in thelongitudinal direction substantially the same as the nominal linearspeed; and depositing transverse bands of the add-on slurry onto thefibrous web through the orifices, where the length of each transverseband is no greater than the portion of the wire width corresponding tothe distribution device.
 2. The method of manufacturing of claim 1including: delivering the add-on slurry to the reservoir of eachdistribution device; and depositing transverse bands of add-on slurry ina plurality of longitudinally extending zones which are parallel to eachother and together extend substantially across the wire width.
 3. Themethod of manufacturing of claim 1 further including the step of:slitting the web into at least two narrower webs, each narrower webhaving a width corresponding to the distribution device which depositedtransverse stripes thereon.
 4. The method of manufacturing of claim 3,including the further step of: independently reeling each of thenarrower webs for subsequent use.
 5. The method of manufacturing ofclaim 1 further including the steps of: optically inspecting thetransverse stripes on the web to determine width, and spacingcharacteristics; and dynamically adjusting operation of at least one ofthe distribution devices in response to the optical inspection step toprovide uniform width and uniform spacing of the transverse stripes onthe web.
 6. The method of manufacturing of claim 1, further includingthe steps of: Supplying the add-on slurry to a plurality of linearlyarranged compartments in the reservoir; and advancing the at least oneorifice sequentially through the plurality of linearly arrangedcompartments.
 7. The method of manufacturing of claim 6, furtherincluding the steps of: optically inspecting the transverse stripes onthe web to determine width and spacing characteristics as a function oflateral location on the web; dynamically adjusting the pressure in eachcompartment of the distribution devices in response to the opticalinspection step to provide uniform width and uniform spacing of thetransverse stripes on the web.
 8. The method of manufacturing of claim1, wherein the first slurry and the add-on material are ingredients ofcigarette paper.
 9. The method of manufacturing of claim 1, wherein thewire has a width greater than three meters and the linear speed is morethan 500 ft./min.
 10. Apparatus for manufacturing a web having anapplied pattern of add-on material comprising: a Fourdrinier wireoperable to prepare a continuous web of fibrous material which moves ina longitudinal direction at a nominal linear speed, has a widthtransverse to that longitudinal direction, and a generally planarsurface; at least two distribution devices, each operable to deposit astream of add-on material on the generally planar surface of the web,each having a reservoir for add-on material, a principal length, and acontinuous belt operable to move between the reservoir and the planarsurface at a belt speed, including at least one orifice, such that whenthe orifice aligns with the reservoir a stream of add-on material isdeposited on the generally planar surface; each distribution devicebeing angled with respect to the longitudinal direction such that eachdistribution device covers a corresponding portion of the web width; thebelt speed having a longitudinal component generally parallel to thelongitudinal direction and a transverse component generallyperpendicular to the longitudinal direction, the longitudinal componentbeing substantially equal to the nominal linear speed; and a controlsystem selectively operating each of the distribution devices.
 11. Theapparatus of claim 10, wherein: each distribution device covers aportion of the width of the web; and each distribution device deposits aplurality of generally horizontal bands of add-on material on thesurface of the web.
 12. The apparatus of claim 10 further including acutting device to longitudinally slit the web into parallel narrowerwebs, each narrower web having a width corresponding to a banded regionformed by the respective distribution device.
 13. The apparatus of claim10 further including: a drying system operable to dry the web,positioned downstream of the distribution devices; an optical inspectionsystem operable to determine the width of the bands of add-on material,positioned downstream of the drying system, operably connected with thedistribution devices; and a control system responsive to the opticalinspection system to adjust add-on material supply to the distributiondevices to provide bands with uniform width and/or thickness.
 14. Theapparatus of claim 10 further including: a drying system operable to drythe web, positioned downstream of the distribution devices; an opticalinspection system operable to determine the spacing between the bands ofadd-on material, positioned downstream of the drying system, operablyconnected with the distribution devices; and a control system responsiveto the optical inspection system to adjust operation of distributiondevice belt speed to provide bands of uniform spacing.
 15. The apparatusof claim 10 further including: a drying system operable to dry the web,positioned downstream of the distribution devices; an optical inspectionsystem operable to determine the uniformity and spacing of the bands ofadd-on material, positioned downstream of the drying system and operablyconnected with the distribution devices; and a control system responsiveto the optical inspection system to adjust operation of the distributiondevices to provide bands with uniform width and spacing.
 16. Theapparatus of claim 10 wherein the distribution devices are parallel toone another and laterally offset.
 17. The apparatus is a cigarette papermaking machine.